1,709 research outputs found
Aphasia with anatomical isolation of the language area: A reanalysis on the light of modern neuroimaging techniques
Introduction : Goldstein (1948) and Geschwind (1968), based in data derived from anatomical post-mortem studies, postulated that the disconnection of the perisylvian language areas (PSLA) from other cortical areas was responsible for impairments in spontaneous speech and language comprehension with preservation of verbal repetition and echolalia (isolation of speech area). Nevertheless, other mechanisms (right hemisphere or bilateral hypotheses) underlying echolalic repetition have been proposed. Herein, we examined the structure and function of the PSLAs in two cases of aphasia with echolalic repetition and isolation of the left PSLA.
Methods : Two patients with chronic post-stroke aphasia associated to isolation of the left PSLA were studied. Both patients underwent cognitive-language assessment and multimodal imaging. In patient 1 (p1), structural MRI, diffusion tensor imaging (DTI), functional MRI (fMRI) during repetition of words and non-words, resting
state fMRI (rsfMRI) were acquired, whereas only structural MRI was performed in patient 2 (p2). The Tractotron software was used to examine the severity of disconnection in each language-related white matter tract in both patients. We quantified the severity of the disconnection by measuring the proportion of each tract that was affected. 18FDG-PET was also acquired in both patients.
Results : P1 had a mixed transcortical aphasia and p2 had a transcortical sensory/anomic aphasia. In both, the
MRI showed separate left anterior and posterior lesions with relative preservation of the PSLA. In both, 18FDG-PET revealed significant decrements of metabolic activity in areas of the left PSLA, although some parts showed normal metabolic activity. In p1 the left arcuate fasciculus (AF) and the inferior fronto-occipital fasciculi (IFOF) could not be reconstructed. fMRI showed perilesional activity in the left hemisphere and increased activity in the right during word repetition. rsfMRI showed compensatory activity in both hemispheres (right greater than left). Analysis with the Tractotron software revealed disconnection of both the AF and the IFOF in the left hemisphere of both patients.
Discussion : Although some parts of the left PSLA had preserved metabolic activity in both patients, our neuroimaging data revealed that preserved repetition ability did not rely exclusively on the residual activity of the left PSLA. In support, the connectivity between different components of the left PSLA was severely affected. This coupled with the increased metabolic activity of the right PSLA supports the bilateral hypothesis of residual repetition in transcortical aphasias.
References : Goldstein, K. (1948). Language and Language Disturbances.
Geschwind, et al. (1968). Neuropsychologia 6, 327–340.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Ferrocene-Decorated Phenol Derivatives by Trapping ortho-Quinone Methide Intermediates with Ferrocene
The InCl3-catalyzed reaction of ferrocene with ortho-hydroxybenzyl alcohols is reported and represents a convenient route for the synthesis of ferrocenyl phenols. This carbon–carbon bond forming process is believed to proceed through an ortho-quinone methide intermediate that can be intercepted by ferrocene through a Friedel–Crafts-type process. Preliminary cytotoxic screening carried out on several cancer cell lines revealed that some of the compounds exhibit moderate cytotoxicity
“Need to know” and the right temporal lobe: Impaired access to semantic knowledge in acquired obsessive-compulsive disorder?
Introduction : Idiopathic obsessive-compulsive disorder (I-OCD) has been linked to abnormalities in corticostriatal circuits. Few studies have examined if the same structures are also responsible of acquired OCD (A-OCD) or if damage to anatomically-connected brain regions (e.g., temporal lobes) are also implicated in its
pathogenesis. Additionally, there are some discrete obsessive-compulsive (OC) symptoms that by virtue of their presumed low occurrence and difficultly of categorization have received less attention. Amongst these, one intriguing and potentially severe type of obsessive thinking is the so-called “need to know” (NtK), a strong drive to know and obtain given information. In some patients this specific symptom, presumably resulting from impaired access to conceptual knowledge for specific verbal information (proper names, names of places), may be the principal or major feature of OCD symptomatology. We here report the cases of two male patients who developed “NtK” as the only OC symptomatology in association with malignant neoplasms involving the right temporal lobe and connected corticostriatal circuits.
Methods : We used Tractotron and Disconnectome map softwares in order to identify the regions of white matter damage overlap across both patients and the proportion of damage (lesion load) of each tract of interest for each patient. We quantified the severity of the disconnection by measuring the proportion of each tract of interest to be affected by each patient´s lesion by using Tractotron software. Additionally, Positron Emission Tomography was used in order to study metabolic abnormalities. The tracts of interest were: the uncinate fasciculus, the anterior commissure, the anterior thalamic radiations, the inferior fronto-occipital fasciculus and the inferior longitudinal fasciculus.
Results : There was a high overlap across brain lesions in patients 1 and 2. There was also a high overlap between areas that were affected (disconnected) due to the lesion. As expected, all the a priori selected pathways in the right hemisphere were affected since they cross the anterior part of the temporal lobe. Disconnection maps
and metabolic changes in our patients suggest that the expression of OC symptoms underpinned by a semantic deficit due to right temporal damage is secondary to involvement of the uncinate fasciculus linking the temporal pole with the orbitofrontal cortex.
Discussion : Data from the present study concur with previous research on A-OCD and current findings in I-OCD which suggest that the temporal lobes participate in the phenomenological expression of OCD. Also, patients with lesions in the anterior temporal lobe are prone to show a specific “Need to Know” symptoms phenomenologically similar to patients with semantic dementia in later stages. The expression of OC symptoms underpinned by a semantic deficit because of anterior right temporal lobe lesion, are due to a disconnection of the uncinate fasciculus and the orbitofrontal cortex. Further research about the neurological underpinnings of specific OCD subtypes, its evaluation and treatment, are essential.
References : Berthier ML et al. Neurology. (1996) 47: 353–61. Huey E et al. J Neuropsych Clin Neurosci (2008). 20(4):390-408
Keywords : Emotions & Social Cognition; patients; single case study; adults; psychiatric; lesion mapping, behavioural.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Generation of H₂ on Board Lng Vessels for Consumption in the Propulsion System
[Abstract] At present, LNG vessels without reliquefaction plants consume the BOG (boil-off gas) in their engines and the excess is burned in the gas combustion unit without recovering any of its energy content. Excess BOG energy could be captured to produce H₂, a fuel with high energy density and zero emissions, through the installation of a reforming plant. Such
H₂ production would, in turn, require on-board storage for its subsequent consumption in the propulsion plant when navigating in areas with stringent anti-pollution regulations, thus reducing CO₂ and SOₓ emissions. This paper presents a review of the different H₂ storage systems and the methods of burning it in propulsion engines, to demonstrate the energetic viability thereof on board LNG vessels. Following the analysis, it is identified that a pressurised and cooled
H₂ storage system is the best suited to an LNG vessel due to its simplicity and the fact that it does not pose a safety hazard. There are a number of methods for consuming the H₂ generated in the DF engines that comprise the propulsión plant, but the use of a mixture of 70% CH₄-30% H₂ is the most suitable as it does not require any modifications to the
injection system. Installation of an on-board reforming plant and H₂ storage system generates sufficient H₂ to allow for almost 3 days’ autonomy with a mixture of 70%CH₄-30%H₂. This reduces the engine consumption of CH₄ by 11.38%,thus demonstrating that the system is not only energy-efficient, but lends greater versatility to the vessel
Diseño de un modelo de compras técnicas para empresas de manufactura
El objetivo general del presente proyecto consiste en diseñar un modelo que
contribuya al mejoramiento de los procesos de compras para el incremento de la
productividad de pequeñas y medianas empresas en el sector manufacturero.
Para cumplir con el objetivo propuesto se realizo una encuesta a diferentes
empresas del sector manufacturero de Cali para ver la situación actual dentro de
las organizaciones, por medio del análisis del departamento de compras con que
cuentan estas organizaciones. Evaluando y definiendo los criterios y lineamientos
a la hora de hacer adquisiciones en la organización.
Elaborando una herramienta en la cual nos podemos apoyar como complemento
ideal para el departamento de compras en el sector manufactureroTesis (Ingeniero Industrial)-- Universidad Autónoma de Occidente. División de Ingeniería, 2005PregradoIngeniero(a) Industria
Treatment of temporomandibular myofascial pain with deep dry needling
Objectives: The present study was designed to evaluate the usefulness of deep dry needling in the treatment of temporomandibular myofascial pain. Study D esign: We selected 36 patients with myofascial pain located in the external pterygoid muscle (30 women/6 men, mean age=27 years with SD±6,5). We studied differences in pain with a visual analog scale and range of mandibular movements before and after intervention. Results: We found a statistically significant relationship (p<0,01) between therapeutic intervention and the improvement of pain and jaw movements, which continued up to 6 months after treatment. Pain reduction was greater the higher was the intensity of pain at baseline. Conclusions: Although further studies are needed, our findings suggest that deep dry needling in the trigger point in the external pterygoid muscle can be effective in the management of patients with myofascial pain located in that muscle
Prevalencia de caries severa temprana de la infancia en pacientes que acuden a la clínica de la especialidad en Odontopediatría UAEM de Febrero 2006-Mayo del 2012
1571 expedientes fueron analizados, 1335 correspondieron a niños con CSTI. La prevalencia de caries fue de 85%, 699 (52.4%) del sexo masculino y 636 (47.6%) del sexo femenino. El grupo de edad más afectado por CTIS fue el de 37 a 48 meses en ambos géneros.Los niños más pequeños son los más susceptibles a padecer caries, debido a que presentan un esmalte poco mineralizado, dependen de los alimentos que les proporcionan sus padres y además la falta de información sobre la práctica de higiene oral en casa a edades tan tempranas
Multiciliated ependyma recovery through a sequential cell therapy in posthemorrhagic hydrocephalus.
Posthemorrhagic hydrocephalus (PHH) is a significant cause for premature children’s morbidity, mortality, and
peri/postnatal neurodevelopmental impairment. PHH is mainly triggered by germinal matrix hemorrhages (GMH)
and causes germinal matrix and ependyma disfunction. Ependyma constitutes a relevant tissue barrier with roles in
cerebrospinal fluid homeostasis, circulation, and neurogenesis, hence situating ependyma as a main target when
treating PHH. Clinical treatments are directed to eliminate immediate inflammatory condition triggered by the
bleeding, to drain excess of CSF if needed, but not to treat or recover ependyma structure. Ependymal progenitors
were obtained from P0 mice. Cells were cultured under specific conditions to enhance either ependymal
proliferation or differentiation status. Different GMH/IVH neuroinflammatory conditions were mimed in the
ependyma cultures, different stem cell therapies tested and effect on the ependymal differentiation measured.
Additionally, ventricular wall explants from mice with induced PHH were obtained and cultured as ex-vivo system of
PHH. A combination of stem cells was applied on the tissue to probe its regenerative capabilities on the
multiciliated ependyma. All samples were analyzed through immunofluorescence and laser confocal microscopy
and quantified. Results show that (i) ependymal progenitors’ maturation is hindered under neuroinflammatory
conditions, showing no multiciliated ependyma and (ii) the tested stem cell combination promotes ependymal
progenitors’ survival albeit does not alter the differentiation of the selfsame. In summary, it can be stated that the
final differentiation of the ependyma is disrupted by the molecular conditions triggered by GMH/IVH, which our
proposed cell therapy is able to counteract through increased survival and differentiation in a murine model of
experimental PHHJunta de Andalucia (UMA18-FEDERJA-277) and Instituto de Salud Carlos III
(PI19/00778), Spain; co-financed by FEDER funds from the European Union, Spain. Also, II-PPITD, Universidad de
Malaga, Spain (to JL-dSS); and I-PPITD, Universidad de Málaga, Spain (to LMR-P)
Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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